Normal breathing occurs when the central nervous system properly functions and sends signals instructing the body to breathe and obstructions to the airway are not present. Disordered breathing occurs when a patient experiences insufficient respiration with or without respiratory effort. Disordered breathing events may be classified by origin. For example, disordered breathing can originate from a deficiency in the central nervous system (central disordered breathing) or from an obstructed airway (obstructive disordered breathing).
Central disordered breathing is caused by a disruption of the nervous system signals that control breathing. During central disordered breathing events, the patient makes no effort to breath or the respiratory effort is insufficient.
Obstructive disordered breathing generally occurs due to an obstruction of a patient's airway. For example, the patient's tongue or other soft tissue of the throat may collapse into the patient's airway. The breathing reflex is triggered, the patient attempts to breathe, but respiration is disrupted because of the occluded airway. Disordered breathing events may involve central disordered breathing, obstructive disordered breathing, or a mixture of obstructive and central types of disordered breathing.
Although episodes of disordered breathing can occur when the patient is awake, they more often occur during sleep. Sleep apnea is characterized by periods of interrupted breathing during sleep. Hypopnea is another form of disordered breathing characterized by periods of shallow breathing. Sleep apnea, hypopnea and/or other forms of disordered breathing events may be associated with central, obstructive, or mixed disordered breathing origins. Other forms of disordered breathing that may be classified according to origin may include, for example, tachypnea (rapid breathing), hyperpnea (heavy breathing), dyspnea (labored breathing), and periodic breathing (periodically waxing and waning respiration).
A severe form of disordered breathing that generally includes periods of central sleep apnea is known as Cheyne-Stokes respiration (CSR). CSR is a type of periodic breathing marked by periodic patterns of waxing and waning respiration interrupted by periods of central apnea. CSR is commonly associated with poor prognosis when diagnosing congestive heart failure (CHF) patients.
Classification of disordered breathing events by origin, e.g., central, obstructive, or mixed, may be used to enhance the diagnosis of disordered breathing. Therapy for disordered breathing and other conditions may be more effectively provided with knowledge of the origin of breathing disorders experienced by the patient.